|
|
There are 20 feet of blood vessels in each square inch of human skin.
Intradermal injections are somewhat difficult to correctly administer because the skin layers are so thin that it is easy to accidentally punch through to the deeper subcutaneous layer.
Liver spots have nothing whatsoever to do with the liver. They are a type of freckles commonly seen in older adults who have been out in the sun without sufficient sunscreen.
Acute bronchitis is an inflammation of the breathing tubes (bronchi), which causes increased mucus production and other changes. It is usually caused by bacteria or viruses, can be serious in people who have pulmonary or cardiac diseases, and can lead to pneumonia.
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.